[CMake] Support for Compaq Visual Fortran under Windows

[Arjen Markus]

Hello,

I recently submitted the request to add a module for the Compaq Visual 
Fortran
compiler (#3950). I can now confirm that this module works not only for 
a small
standalone Fortran program, but it also works for the PLplot project 
where I
can build shared libraries (DLLs if you will) that depend on other 
libraries,
written in C, instead of Fortran.

So, I am confident that it is useable and useful and I would like to see 
it incorporated
in the next version of CMake. It was written by Philippe Poilbarbe and I 
have merely
added a single option so that the problems he had were solved (credits 
to Philippe
and Brad for this).

Regards,

Arjen